Repair patch for rubber articles



May 9, 1953 W. GRUBER REPAIR PATCH FOR RUBBER ARTICLES Filed Ju'ly 29, 1.949

INVENToR. W'I'ZZ/z/ Gra/ber orneys.

body layer to the main substance of the main body. This good transition guarantees that the repair patch will adhere well and lastingly to the tube and the effect is that, even if the puncture has to take up great strain placed on it as a result of vibration, fulling effect and the like, the repair patch cannot become detached.

Fig. 4 illustrates the interior of a tire 5 with the customary attaching flanges-6 and beads 'I and showing a `damaged part 8 to which a repair patch 9 is applied. This patch also has a thin connecting layer as illustrated in Fig. 1. According to the invention, this connecting layer has an overlapping or laterally 'projecting rim I0 extending completely around the body layer of the patch and thus insuring the lasting adhesion of the repair patch 9 to the inside of the tire.

In a special modification the connecting layer has -a different color from that of the body layer of the repair patch and/or the tube or tire needing repair so that at 4 and/or I0 there is a colored rim, for example a red lor yellow rim. This has the technical advantage that even in a bad light a previously repaired puncture in the tube or tire can be recognized immediately and can be tested as to compactness.

Of course, in the case of all connecting layers of the repair patch, a detachable protective layer II, for example of paper, cellophane or similar substance, can be applied over the connecting layer.

In a particularly advantageous system a thin cover layer Ia of paper, cellulose or similar substance is applied over the outside surface of the patch I, which also covers the rim 4 of the attaching layer and which can be removed, for example by washing off, after the patch has been applied to the tube. This cover layer greatly supports the application without creases of even a thin outside rim on the patch as well as the firm adhesion of the rim 4 of the connecting layer to the tube.

With a modification the connecting layer has a greater coefficient of elongation than the main body.

The most suitable combination for cold vulcanisation is a main body layer I of vulcanized rubber and a connecting layer 3 of unvulcanized rubber containing sulphur or sulphur composition. As one particular modification the connecting layer consists of pure unvulcanized caoutchouc which is only able to act as connecting means between the patch and the article to be repaired when sulphur and accelerator agents are added just before the patch is applied to the article to be repaired. This kind of modication has the advantage that the patch has an almost unlimited durability.

For the purpose of hot vulcanisation the mainbody may consist of unvulcanized rubber.

In a further modification the main body of the patch consists of a plurality of superposed layers of unvulcanized rubber I2, I3, I4, decreasing in lateral dimensions and combined by a rubbetlf solution, Figures 5 and 7. A connecting layer I5 as described before is attached to the lowermost layer, and has a larger diameter than the lowermost layer I3 or I4 respectively, and thus providing a projecting rim I6. I1 and a cover layer I8 may be also provided similar tothe layers II and la of Figures 1 and 3. Figure 6 illustrates how the layers I2 and I3 upon the application of heat and pressure melt together and in unison with the connecting layer I5 close a slit I9 in the Wall a. of a tube and provide an enlargement 20 in the width of the patch.

Such repair patches are also suitable for the repairing of the tops of motor` vehicles, rubberized covers or awning members, rubber coats, and rubber shoes.

Such repair patches are useful in combination with vulcanisation fluid, that is a solution of rubber in benzine, benzol or the like containing accelerators. Accelerators are ingredients well known in the art accelerating and facilitating vulcanisation. Preferably this fluid is put on the subject to be repaired in a thin layer and when dried, the repair patch is applied to it.

It is therefore clear that this invention provides a repair patch for rubber arti-cles that comprises a body layer I of vulcanized rubber and a thin attaching or connecting layer 3 of flexible unvulcanized rubber. The body layer has a flat bottom and the attaching layer is secured thereto.

Furthermore the body layer has a graduated A protective laye'rt'fo thickness as clearly shown in the drawings including a central portion of substantial thickness in relation to the thickness of the attaching layer of unvulcanized rubber and a thin flexible perimetrical rim portion. Thus as shown, the upper surface of the body layer tapers laterally outwardly from the central portion to the periphery to form a thin tapered rim 2. The thin layer of unvulcanized rubber, that is the attaching or connecting layer, has a substantially greater area than the area of the body layer so that the perimeter of the body layer is disposed inwardly of the perimeter of the attaching layer to provide a thin ilexible marginal rim of substantial width and of unvulcanized rubber that extends laterally outwardly of the tapered rim 2 of the body layer. This insures that the patch can effectively adhere to a rubber article to be repaired without knurling, wrinkling or loosening of the thin tapered rim of the body layer and with equalized tension existing between the body layer and the article to be repaired, particularly pneumatic tire tubes.

What Iclaim is:

1. A repair patch for rubber articles comprising a body layer of vulcanized rubber and a thin attaching layer of flexible unvulcanized rubber, said body layer having a at bottom and said attaching layer being secured to said bottom, said body layer further having graduated thickness including a central portion of substantial thickness in relation to the thickness of the layer of unvulcanized rubber and a thin flexible perimetrical rim portion, the upper surface of said body layer tapering laterally outwardly from the central portion to the periphery to form the thin tapered rim, said thin layer of unvulcanized rubber having a substantially greater area than the area of the .body layer so that the perimeter of the body layer is rdisposed inwardly of the perimeter of the attaching layer to provide a thin flexible marginal rim of substantial width and of unvulcanized rubber extending laterally outwardly of the tapered rim of the body layer so that the patch can effectively adhere to a rubber article to be repaired without knurling, wrinkling or loosening of the thin tapered rim of the body layer and with equalized tension between the body layer and the article to be repaired.

2. A repair patch for rubber articles as claimed in claim 1 and a removable protective covering layer on the outer` surface of said attaching layer of substantially greater area than the area of the body layer.

3. A repair patch for rubber articles as claimed in claim 1, including a removable protective covering layer on the outer surface of said *attach* ing layer, an additional removable protective covering layer on the outer surface of the body layer and both protective covering layers having a substantially greater area than the area of the body layer.

4. A repair patch for rubber articles as claimed in claim 1, in which the thin attaching layer has a thickness less than 1 mm. and the flexible marginal rim of the attaching layer that extends laterally outward of the rim of the body portion having a lateral extent substantially many times larger than the thickness of the attaching layer.

5. A repair patch for rubber articles as claimed in claim 1, particularly for repairing punctures in pneumatic tire tubes and said attaching layer having a vcolor different than the color of the body layer so as to facilitate recognition of a previously repaired puncture in a tube.

WILLY GRUBER.

References Cited in the flle of this patent UNITED STATES PATENTS Number 5 Re. 17,859 Re.17,860 995,106 1,503,701 1,629,335

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